a hypothesis must be testable through experimentation, observation, or mathematical demonstration

A theory, as used in scientific discourse, is:

a set of principles, supported by evidence, that explains some aspect of nature

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Pasteur's experiments on spontaneous generation made correct use of a variable in that Pasteur:

held all conditions constant in each test except one

Biologists generally define life in terms of a group of characteristics possessed by living things. What is NOT a characteristic of living things?

all living things are composed of two or more cells

Evolution is a central, unifying theme in biology because:

the enormously diverse forms of life on Earth have all been shaped by it

Biology is defined as:

the study of life

life exists:

almost everywhere on earth

What is NOT a common characteristics of living things

they use other cells for reproduction

Living organisms are assigned into groups based upon their

similarities

The largest classification of living organisms is called the :

domain

in classification of living organisms, which are the names of the domains?

archaea, bacteria, and eukarya

humans depend on healthy ecosystems for our own survival

true

how many kingdoms are there in the domain eukarya?

4

in the classification of living organisms, which of the following is the most inclusive level ?

kingdom

what is the proper terminology for the classification of modern humans?

homo sapiens

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humans modify ecosystems to improve the ecosystem?

false

the process that biology and other scientific fields use to study a question is called:

scientific method

what are examples of theories in biology

cell, germ, evolution, and gene

a hypothesis is:

a tentative explanation of a natural event

A ______ is a conceptual scheme that join together well-supported and related hypotheses.

theory

when most investigators do controlled studies, what do you call the group that does not receive treatment?

control

what is usually the last step in the scientific method

draw a conclusion on the basis of the experiment

the ______ theory enables scientists to understand the history of life, the variety of living things, and the development of organisms

evolution

which theory states that life comes only from life?

biogenesis theory

which sequence correctly increases complexity in the level of biological organization?

atoms, molecules, cells, tissues, organs

a(n) _______ in the lowest level of biological organization to have the characteristics of life.

cell

live exists almost everywhere on earth, such as deep sea thermal vents where the temperature is 700O f

true

what is not a common characteristic of living things?

they are organized

they maintain their internal environment to within a certain defined range.

have the capacity to adapt

they acquire materials and energy

bacteria are single-celled organisms that have a membrane-bound nucleus

false

the earth may be losing as many as 400 species per day due to human activities

true

the "big bang" that produced the universe is thought to have occurred

4.6 billion years ago

when the earth first solidified, what were conditions like?

the atmosphere was rich in gases released in volcanic eruptions, volcanic activity, lighting, and ultraviolet radiation were all much more intense than on today's earth

the earliest discovered fossils are of ____ dating back to _____ years

prokaryotes..... 3.5 billion

the findings of Pasteur and others have established that

life does not arise from nonliving matter today, but in the conditions of early Earth, such an event could have occurred.

Miller was the first to show _____

amino acids and other organic molecules could have been generated on a lifeless Earth

what was the probably role of oxygen gas in the early stages of life's appearance on Earth?

oxygen gas tends to disrupt molecules, so its absence promoted the formation and stability of complex organic molecules on the early Earth

Miller-Urey-type experiments have shown that ________

complex organic molecules can be produced by physical processes from inorganic components

__________ are membranes containing concentrated organic molecules and have some lifelike properties, but are not alive.

protobionts

a current leading hypothesis about the first system of inheritance in the earliest life forms involves__________

self- replicating RNA molecules aided by ribozymes

Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent?

first prokaryotes; photosynthesis; first eukaryotes; colonization or land by plants and fungi

The technique called radiometric dating is based on ___________

the steady, clocklike decay of certain radioactive isotopes over time.

Earth's continents and sea floors together form a thing outer layer of the planet called __________

crust

The Himalayas are an example of a mountain range formed as a result of _____

the collision of two continental plates

during the _____, over 96% of marine species and many terrestrial species became extinct, possibly because intense volcanic activity warmed Earth's climate.

Permian

Mass extinctions _______________

remove well-adapted species and groups from the Earth, so that it may take tens of millions of years for species diversity to recover

According to "evo-devo" thinking, an organism's body form can be substantially changed _____________

through mutations or changes in the expression of one or a few "master" control genes that regulate development.

How can a phylogenetic tree be used to make predictions?

Features shared between two groups are likely to have been present in their common ancestor.

__________ makes it possible to trace phylogenies among microbial groups for which there is no fossil record.

molecular systematics

Which of the following statements regarding genetics is false?

in keeping with our greater complexity, the human genome has about 100 times more genes than that of yeast.

a(n)__________has been used to estimate that HIV-1 M first spread to humans in the 1930s

molecular clock

In the three-domain system, the eukaryotes are represented ____________

only within the domain Eukarya.

The four most common elements in living organisms are ______

C, H, O, N

Which of the following statements regarding matter is false?

all life is composed of matter

matter occupies space

matter has mass

matter is composed of elements

matter can be created and destroyed

Which of the following trace elements is commonly added to table salt to prevent the formation of goiters?

Iodine

Which of the following statements best describes a compound?

a compound contains two or more different elements in a fixed ratio

In the equation 2 H2 + O2 + 2H20, _______

only H2O is a compound

Which of the following particles is found in the nucleus of an atom?

protons and neutrons

What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?

12

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many electrons does boron have?

5

Which of the following is another term used for atomic mass?

dalton

The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium

23

Which of the following best describes the atomic number of an atom

the number of protons in the atom

Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen could _______

have more neutrons

A radioactive isotope is an isotope that _________

decays

If you found a fossilized dinosaur bone, what method could be used to determine the age of the fossil?

isotope analysis

Which of the following statements about radioactive isotopes is true?

the energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells

Radioactive isotopes ____________

can be used in conjunction with PET scans to diagnose diseases

What happens to an atom if the electrons in the outer shell are altered?

the properties of the atom will change

a ___________ forms when two atoms share electrons

covalent bond

A hydrogen atom has one electron. How many covalent bonds can hydrogen form?

one covalent bond

What is the fundamental difference between covalent and ionic bonding?

in a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other

Which of the following statements regarding the oxygen atom of a water molecule is true?

oxygen is more electronegative than the hydrogen atoms

in a water molecule, hydrogen and oxygen are held together by a _______ bond

polar covalent

A water molecule (H-O-H) is held together by ________

two polar covalent bonds

The hydrogen atoms of a water molecule are bonded to the oxygen atom by _______ bonds, whereas neighboring water molecules are held together by ________ bonds.

polar covalent.... hydrogen

__________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bonds within and around large molecules

hydrogen bonds

Water molecules stick to other water molecules because _______

hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules

The tendency of water molecules to stick together is referred to as _____

cohesion

Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water?

the universality of water as a solvent

water's surface tension and heat capacity is accounted for by its_______

hydrogen bonds

as ice melts, _____

hydrogen bonds are broken

The temperature of evaporation is much high for water than for alcohol. Without knowing more about the chemistry of alcohol, which of the following is the most logical chemical explanation for this phenomenon?

fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.

Which of the following statements about water is false?

the hydrogen bonds in ice are less stable then the hydrogen bonds in liquid water.

You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following statements is true?

you've just prepared an aqueous solution

A pharmaceutical company hires a chemist to analyze the purity of the water being used in its drug preparations. If the water is pure, the chemist would expect to find ____________

H2O molecules, H+ ions, and OH- ions

A solution with a pH of 7 is ____________

neutral

Compared to a solution of pH 3, a solution of pH 1 is _________

100 times more acidic

Which of the following statements about pH is true?

an increase in hydrogen ion concentration means a decrease in pH scale units

Household ammonia has a pH of 12; hosehold bleach has a pH of 13. Which of the following statements about them is true?

The storage form of carbohydrates is _____ in animals and _______ in plants.

glycogen...... starch

Which of the following organisms contain the polysaccharide chitin?

crustaceans and insects

A diet high in animal products and hydrogenated vegetable margarine may increase the risk for atherosclerosis. This is because _________

most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats

Because water and oil don't mix, water is not very effective at washing away oily dirt, The ability of soap to mix with both water and oily dirt to be washed away. Which statement provides the most logical chemical explanation for this phenomenon?

Soap molecules have charged regions and neutral regions. The charge regions are attracted to water molecules; the neutral regions are attracted to oils.

Fatty acids are _____

hydrophobic

Which of the following statements regarding triglyceride molecules is true?

triglycerides consist of three fatty acids attached to a glycerol.

Triglycerides are hydrophobic

Triglycerides play a role in energy storage.

Triglycerides are a type of fat

Fatty acids with double bonds between some of their carbons are said to be _______

unsaturated

If you were to add olive oil to your food as part of a diet to lower your risk of atherosclerotic disease, you would use olive oil that _______

is liquid at room temperature

Which of the following statements about animal cell lipids is false?

many lipids function as enzymes

A phospholipid is composed of _________

one glycerol molecule linked to one phosphate group and two fatty acids

Which of the following substances is a lipid?

steroids

A major type of lipid found in cell membranes are ___________

phospholipids

Which of the following statements about anabolic steroids is false?

they promote bone growth

Which of the following statements about enzymes is false?

they are monomers used to build proteins

Which of the following would be correctly classified as a protein?

cellulose

Amino acids can be distinguished from one another by _____

the chemical properties of their R groups

Proteins differ from one another because __________

the sequence of amino acids in the polypeptide chain differs from protein to protein

Glucose molecules are to starch as _______ are to proteins

amino acids

Peptide bonds ________

link amino acids

The primary structure of a protein is ______

the amino acid sequence of the polypeptide chain

Which of the following is an example of secondary structure in a protein?

an alpha helix

The tertiary structure of a polypeptide refers to _______

the overall three-dimensional structure

A protein containing more than one polypeptide chain exhibits the ________ level of protein structure.

quaternary

Which of the following statements regarding nucleotides is false?

nucleotides have a nitrogenous base backbone

Which of the following options correctly pairs a polymer and its monomer?

DNA, nucleotides

DNA differs from RNA because DNA __________

contains thymine in place of uracil

Genetic information is encoded in the ________

sequence of nucleotides in DNA

The development of atherosclerotic disease can result from a diet high in ________

Saturated fats

an oil may be converted into a substance that is solid at room temperature by ________

adding hydrogens, decreasing the number of double bonds in the molecules

Which of the following statements about cells is true?

all cells have internal structures that move

One centimeter = ________ millimeters

10

The idea that all living things are composed of cells and that all cells come from other cells defines ________

cell theory

The diameter of most animal and plant cells ranges from ___________

10 to 100 micrometers

As cell size increases, the __________

volume increases faster than the surface area

Archaea are composed of _______ cells

prokaryotic

Which of the following structures is exclusively associated with prokaryotic cells

nucleoid

The nucleoid region of a prokaryotic cell ________

contains the cell's DNA

___________ cells lack a membrane-enclosed nucleus

prokaryotic

Which of the following structures are used by prokaryotes for attaching to surfaces?

both pili and capsules

The membranous compartmentalization of a cell _______

allows different metabolic processes to occur simultaneously

Which of the following statements about internal membranes in eukaryotic cells is false?

in eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles

You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells ________

is translated by the ribosomes into the amino acid sequence of proteins

The plasma cell produces thousands of antibodies per second. What type of intracellular structure would you expect to be very prominent within the cell?

rough endoplasmic reticulum

The endomembrane system includes all of the following organelles except the ___________

peroxisome

The two main functions of the rough endoplasmic reticulum are the production of ______________

membrane and proteins secreted by the cell

The cells that produce hair contain a lot of __________, while the cells that produce the oils that coat the hair contain a lot of _____________

rough endoplasmic reticulum..............smooth endoplasmic reticulum

The Golgi apparatus ___________

stores, modifies, and packages proteins

Which of the following statements regarding the Golgi apparatus is false?

the Golgi apparatus decreases in size when a cell increases its protein production

Which of the following statements about lysosomes is false?

lysosomes synthesize proteins from the recycled amino acids

When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will _________

undergo self-digestion and die

Which of the following statements about the functions of a plant cell central vacuole is false?

the central vacuole of a plant cell may digest chemicals for recycling

Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell?

The endosymbiosis hypothesis is supported by all of the following pieces of evidence, except the fact that ________

mitochondria synthesize glucose like prokaryotes

Microfilaments differ from microtubules in that microfilaments ___________

are mainly composed of actin, whereas microtubules are composed of tubulin

Which of the following statements about the cytoskeleton is false?

once laid down, the elements of the cytoskeleton are fixed and remain permanently in place

Cilia differ from flagella in that ________

cilia are typically more numerous and shorter than flagella

Most animal cells are ___________

embedded in a extracellular matrix

It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are _________

communicating junctions

Which of the following statements regarding cells is false

all cells have a cell wall.

In general, which of the following is largely responsible for moving substances across the plasma membrane, communicating with other cells, and identifying the cell?

proteins

How are plasma membranes best described?

double layer of phospholipid molecules with hydrophobic tails oriented toward each other

Cystic fibrosis is a genetic disease that leads to the production of very thick mucus in the respiratory tract, causing frequent and serious respiratory infections. What type of membrane protein is being affected in this case?

transport protein

In the process of diffusion ___________

molecules move from an area of greater concentration to an area of lesser concentration

Carbon dioxide crosses the plasma membrane by simple diffusion. What determines the rate at which carbon dioxide enters the cell?

the concentration of carbon dioxide on each side of the membrane

When two solutions that differ in solute concentration are place on either side of a semipermeable membrane and osmosis is allowed to occur, which of the following will happen?

Water will move from an area of low solute concentration to an area of high solute concentration

The activity of the sodium -potassium pump is critically important in maintaining proper ion concentrations across the cell membrane. A similar pump is the glucose pump. Given that, what can you conclude about the sodium-potassium pump?

the pumping mechanism requires energy

Which of the following types of transport does not require the use of a transport protein?

simple diffusion

The concentration of calcium in a cell is 0.3%. The concentration of calcium in the fluids surrounding the cell is 0.1%. How could the cell obtain more calcium?

active transport

Which of the following statements about the movement of charged ions through a membrane is correct?

movement of ions requires a protein passage through the membrane

Large food particles, or perhaps whole organisms, can be engulfed and pulled into the cell by the process of ________

phagocytosis

Coated pits required for which type of membrane transport?

pinocytosis

What is the primary factor that determines if endocytosis or exocytosis would be needed to move a substance across the cell membrane, as opposed to diffusion or osmosis

the size of the molecules being moved

Which of the following processes uses a difference in concentration to transport water molecules across the cell membrane?

osmosis

Which of the following pieces of evidence would suggest that a substance entered a cell via active transport as opposed to passive transport?

ATP was required for transport

Which of the following molecules or ions would normally need to use a membrane protein to move through the cell membrane?

Na+

You are comparing a 25% salt solution to a 5% salt solution. Which of the following statements correctly describes the difference between these two solutions?

the 25% salt solution is said to be hypertonic compared to the 5% hypotonic solution

Exocytosis would move __________

waste materials out of the cell via a vesicle

In endocytosis, a transport vesicle is derived from the ________

plasma membrane

What would happen if you tossed a beaker full of phospholipids into a beaker of oil?

you would expect the fatty acid tails to point out toward the oil and the head groups to point in toward each other

On each side of a semipermeable membrane is a 5% sugar solution. Which of the following statements correctly describes the movement of material in this system?

movement of water is equal between the two sides

Why are ions unable to move freely through the membrane?

ions are charges, so they cannot diffuse through the hydrophobic core of the membrane

Which of the following items would more likely exist within the glycocalyx?

carbohydrates

Which of the following correctly matches a membrane component with its membrane function?

proteins and transport

The plasma membrane is considered a ______

fluid material

Which type of mechanism relies on the fusion of vesicles with the plasma membrane?

exocytosis

Which of the following statements about phagocytosis is true?

phagocytosis brings materials into the cell

Which type of transport could not occur if the cell was inhibited in the production of a particular protein?

facilitated diffusion

Which type of transport could not occur if the cell was inhibited in the production of ATP?

active transport

A flaccid plant cell could occur because _________

the extracellular environment has a higher salt concentration than does the interior of the cell

Steroid hormones move directly through the cell membrane. Why?

These molecules are non polar, so they can diffuse through the hydrophobic interior of the plasma membrane

If the protein required to move glucose into a cell is damaged, what would you expect to occur?

the cell would be unable to transport glucose into the cell.

The head groups of the phospholipids are found on the exterior and the cytoplasmic side of the membrane because ________

they are hydrophilic

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